dask.array.overlap.overlap(x, depth, boundary, *, allow_rechunk=True)[source]

Share boundaries between neighboring blocks

Parameters
x: da.Array

depth: dict

The size of the shared boundary per axis

boundary: dict

The boundary condition on each axis. Options are ‘reflect’, ‘periodic’, ‘nearest’, ‘none’, or an array value. Such a value will fill the boundary with that value.

allow_rechunk: bool, keyword only

Allows rechunking, otherwise chunk sizes need to match and core dimensions are to consist only of one chunk.

The depth input informs how many cells to overlap between neighboring
blocks ``{0: 2, 2: 5}`` means share two cells in 0 axis, 5 cells in 2 axis.
Axes missing from this input will not be overlapped.
Any axis containing chunks smaller than depth will be rechunked if
possible, provided the keyword ``allow_rechunk`` is True (recommended).

Examples

```>>> import numpy as np
>>> import dask.array as da
```
```>>> x = np.arange(64).reshape((8, 8))
>>> d = da.from_array(x, chunks=(4, 4))
>>> d.chunks
((4, 4), (4, 4))
```
```>>> g = da.overlap.overlap(d, depth={0: 2, 1: 1},
...                       boundary={0: 100, 1: 'reflect'})
>>> g.chunks
((8, 8), (6, 6))
```
```>>> np.array(g)
array([[100, 100, 100, 100, 100, 100, 100, 100, 100, 100, 100, 100],
[100, 100, 100, 100, 100, 100, 100, 100, 100, 100, 100, 100],
[  0,   0,   1,   2,   3,   4,   3,   4,   5,   6,   7,   7],
[  8,   8,   9,  10,  11,  12,  11,  12,  13,  14,  15,  15],
[ 16,  16,  17,  18,  19,  20,  19,  20,  21,  22,  23,  23],
[ 24,  24,  25,  26,  27,  28,  27,  28,  29,  30,  31,  31],
[ 32,  32,  33,  34,  35,  36,  35,  36,  37,  38,  39,  39],
[ 40,  40,  41,  42,  43,  44,  43,  44,  45,  46,  47,  47],
[ 16,  16,  17,  18,  19,  20,  19,  20,  21,  22,  23,  23],
[ 24,  24,  25,  26,  27,  28,  27,  28,  29,  30,  31,  31],
[ 32,  32,  33,  34,  35,  36,  35,  36,  37,  38,  39,  39],
[ 40,  40,  41,  42,  43,  44,  43,  44,  45,  46,  47,  47],
[ 48,  48,  49,  50,  51,  52,  51,  52,  53,  54,  55,  55],
[ 56,  56,  57,  58,  59,  60,  59,  60,  61,  62,  63,  63],
[100, 100, 100, 100, 100, 100, 100, 100, 100, 100, 100, 100],
[100, 100, 100, 100, 100, 100, 100, 100, 100, 100, 100, 100]])
```